Railway-traffic-controlling apparatus



Marnh 16 1926.

H. G. BLOSSER RAILWAY TRAFFIC CONTROLLING APPARATUS INVETOR H. 691 a) lmula Original Filed Jan. 8, 1924 Patented Mar. 16, 1926.

UNITED STATES Vi-TATENT orrlcs.

HERMAN G. BLOSSER, F SWISSVALE, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIG-NAL COMPANY, OF PENNSYLVANIA.

SWISSVALE, PENNSYLVANIA, A GORORATION OF RAILWAY-TRAEFIC-CONTROLLING- APPARATUS.

Application 'led January 8, 1924, Serial T0 all whom, it may concern:

lle it known that l, HERMAN G. Brossura,

a citizen of the United States, residingl at Sivissvale, in the county of Allegheny anc State oit Pennsylvania, have invented certain new and uset'ul Tmproveinents in llailway*Traino-Controlling Apparatus, .of which the following is a specitication.

My invention relates to railway trutlic controlling` apparatus, andA particularly to apparatus of the type comprising loop circuits or local circuits `for the control of train carried governing means.

I will describe one form or traclrway apparatus embodying;` my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic vieiv showing' one torni of traclrway apparatus embodying my invention.

Referring to this drawing' the reference characters l and ln designate the tract: rails oit an electric railroad. `Parallel with these trac-lr rails is a third rail or trolley 6. An impedance is connected across the rails ot the stretch, and alt rnating propulsion current is supplied to the rails through impedance 5 and to the trolley 6 .tromsome suitable source as an alternatorll. The track rails l and l:l are divided., by means ot' insulating joints 2, into a plurality oi successive traclr sections A l, l--Cc CMD, etc.

Propulsion current is conducted past pair of insulated joints by an impedance bond H. llelerringl particularly to the iinpedance bond located at point B, this bond comprises two impedances and 3 connected across the right handend ot section A-B and the lett hand end of section Buti, respectively.' The mid pointst ot these two impedances are connected lto- @other by a conductor fl in the usual manier.

Each nraclr section is provided with a loop circuit over which loop current lloivs to control tratiic through the stretch in any desired manner. This loop current is supplied from loop transformers designated by the reference characters T with appropriate distingguishing` exponents. The primary l8 of each such transformer T is constantly supplied with alternating current of la freinfill Acc- No. 634,962. Renewed January as, 192e.

quency diliierent Afrom the frequency ot the propulsion cir-rent from an alternator G over line Wire 7 and 7;

Referring particularly to section lli-ll, the loop circuit for this section passes from secondary l0 of Aloop transliormer TB, through Wire 2l, impedance 20, Wire primary 1l of an auxiliary transformer li?, Wires 18, l? and Il, impedance 3 at peint A, through the rails of section iti- B in parallel, to impedance 3 at point l5, and Wires 4r, 16 and l5 back to secondaryl) of transformer TB. The loop circuit for section B C may be traced from the secondary 9 or transformer TB, tl'irough wire Q7, impedance 2G, wire 25, primary ll of auxiliary transformer K3, Wires .9J-lf, 23 and et, in'ipedance 3 at point C, through both rails ol section lil-C in parallel to impedance a at point B, thence by Wires l, i6 and 22 back to secondary 9 or' transformer TB. y

The purposes of impedances 2O and is to regulate the amount and` phase of loop current in the associated circuits.

Under certain conditions ot operation the propulsion current 'flowing in the rails creates a potential dill'eence between the ends ot the track sections. This potential ditllerence, in the absence of any preventative means may result in an excessive current through the loop circuit which current may destroy the impedances Q0 and 2S and the windings 9 and 10 ot transformers T. To prevent such occurrence l tune the sec* ondary Windingr 12 or each auxiliary trans former K to approximate resonance at the frequency of generator G by means oi' a reactor 13 and a condenser 14;. It follovs that the transformers l will oller coinparatively 4small impedance to loop currents, but that propulsion current llowing in the loop circuits is opposed by a comparatively high impedance. As a result the propulsion current through the loop circuits is reduced to a comparatively low value.

The small amount of propulsion current which does flow in the loop circuits is prevented trom feeding back into line wires 7 and 7 Vby reversing the connections of the local transformer secondaries for adjacent sections. Thus local current for section B-C flows through secondary 9 of transformer TB in one direction and the local current for section A-B flows through secondary l0 of this transformer in the other direction. These two currents balance each other and therefore the feed back of propulsion current to the signal line wires is prevented.

Although l have herein shown and described only one form and arrangement of railway traliic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. -A railway trafiic controlling apparatus con'iprising astretch of railway track, a loop circuit including the two rails of the stretch in multiple and a source of alternating current, and means associated with said circuit responsive to the frequency of the current supplied thereto.

2. Railway trafiic controlling apparatus comprising a stretch of railway track having propulsion current flowing therein, a loop circuit including the two rails of the stretch in multiple, and frequency responsive means associated with said loop circuit for preventingthe flow of propulsion current in said circuit.

3. Railway traflic controlling apparatus comprising a stretch of railway track having alternating propulsion current of one frequency fiowing therein, a loop circuit including the two rails of the stretch in multiple and a source of alternating current of a different frequency, and frequency responsive means associated with said circuit for preventing current of the frequency of said propulsion current from iiowing in said loop circuit.

Railway traffic controlling apparatus comprising a stretch of railway track having` alternating' propulsion current of one frequency flowing therein, a loop circuit including the two rails of the stretch in multiple and a source of alternating current of a different frequency, and means associated with said loop circuit for offering a high impedance to said propulsion current but for offering a low impedance to current from said source.

5. Railway trafiic controlling apparatus comprising a stretch of railway track having propulsion current flowing therein, a loop circuit including` the two rails of the stretch in multiple, a loop transformer. for supplying alternating current to said loop circuit, andfrequency responsive means for preventing the flow of propulsion current through said transformer. A

G. In combination, a stretch of railway track, a loop circuit for said stretch including the two rails of the stretch in multiple and a source of alternating current, and a transformer having one winding included in said loop circuit and a second winding tuned to approximate resonance at the frequency of said source.

7. vRailway tra'iiic controlling apparatus comprising a plurality of successive sections of railway track, a loop circuit for cach scf:- tion including the two rails of the section in multiple, a source of energy for supplying alternating loop current to cach said section, and a transformer for each section having one winding included in the correspcnding loop circuit and a second windu tuned to approximate resonance at the ii zency ot" the loop current supplied to said circuit.

23. Railway trailic controlling apparatusy comprising a. forward and a rear slction oi' railway track, means for supplying propulsion current to the rails of said sections, a loop circuit for each said section including at least one rail of the associated tion, means for supplying alternating loop current of one relative polarity to one such loop circuit and for supplying alternating loop current of the other relative polarity to the other loop circuit, and frequency responsive means for each said loop circuit for preventing propulsion current from flowing in such circuit.

0. In combination, two successive sections of railway track, and means for causing alternating train controlling loop current to flow in the two rails in multiple of cach section in such manner that at any given irstant the directions of flow in the two scctions are opposite.

l0.- In combination, two successive sect-ions of railway track carrying alternating electric propulsion current, a train control transformer having a primary supplied from an alternating current transm` ion line and two secondaries, and a loop circuit for earl section including the rails of the section in multiple and one of said secundarios, the secondaries being so connected that at any given instant the directions of tiow of loop current in the two sections are opposite whereby equal amounts of propulsion current ilowing in said two loop circuits will have equal and opposite effects on the primary of said transformer and so will create no flow of propulsion current in said transmission line.

l1. .In combination, two successive sections B-C and C--D of railway track, an impedance connected across the track rails of each section at each end of the section, a trainV control transformer having a primary supplied with alternating current and two secondaries, means for connecting two like terminals of said two secondaries with the two impedances adjacent the junction of loo lll)

said sections, and means for connecting the other two secondary terminals with the other two impedances respectively.

12. In combination, two successive sections of railway track, a train control transformer having a primary supplied with alternating current and two secondaries, andV loop circuits for said sections including the track rails in multiple and said two secondaries respectively, said secondaries being so connected that at any given instant the directions of flow of loop currents in the two sections are opposite.

13. In combination, two successive sections of railway track, a train control transformer having a primary supplied with alternating current and two secondaries, and means including said sccondaries for supplying loop currents of opposite instantaneous relative polarities to said two track sections.

1li. ln combination, two successive sections of railway track carrying alternating electric propulsion current of one frequency, a transformer having a primary supplied from a transmission line carrying train control current of a different frequency, said transformer having two secondaries, and means including said secondaries for supplying loop currents of opposite instantaneous relative polarities to said two track sections.

15. In combination, two successive sections of railway track carrying alternating electric propulsion current of one frequency, a transformer having a primary supplied from a transmission line carrying train control current of a different frequency, said transformer having two secondaries, means including said secondaries for supplying loop currents of opposite instantaneous relative polarities to said two track sections, and frequency responsive means associated with the loop circuit of each section for freely transmitting` train control current but opposing the iiow of propulsion current.

16. Railway traffic controlling apparatus comprising a stretch of railway track having propulsion current flowing in the rails thereof, a loop circuit including the two rails of the stretch in multiple and a source of loop current, and means tending to prevent propulsion current from flowing in said loop circuit.

17. Railway tra'liic controlling apparatus comprising a stretch of railway track having propulsion current flowing in the rails thereof, a` loop circuit including the two rails of the stretch in multiple and an impedance element, and means for reducing the impedance of said element to loop current but not to propulsion current.

18. Railway traffic controlling apparatus comprisingl a stretch of railway track having propulsion current flowing therein, a local transformer, a loop circuit including the two rails of said stretch in multiple and a winding of said transformer, and means for preventing the flow of propulsion current in said transformer.

19. In combination, a plurality of successive sections of railway track having propulsion current flowing therein, impedance bonds for conducting propulsion current from each section to the adjacent sections a loop circuit for each section includij the two rails off the section in multiple and an impedance, and means associatedv with each such circuit for preventing the-flow of propulsion current through such impedances.

20. In combination, a plurality of successive sections of railway track having propulsion current iiowing therein, impedance bonds for conducting propulsion current from each section to the adjacent section, a loop circuit for each section including the two rails of the section in multiple and an impedance, and a second impedance for each such circuit for preventing the flow of propulsion current through such first impedances.

In testimony whereof l affix my signature.

HERMAN G. BLOSSER. 

